kernel panic after LVM setup

Posted by Manuel Sopena Ballesteros on Server Fault See other posts from Server Fault or by Manuel Sopena Ballesteros
Published on 2014-08-22T13:31:56Z Indexed on 2014/08/23 4:22 UTC
Read the original article Hit count: 540

I broke my webserver...

My setup is:

  • VMWare ESXi environemt
  • CPanel installed
  • CentOS release 6.5 (Final)
  • 4 CPUs
  • 2G RAM
  • 2x VM disks 100G each
  • LVM system

This was my previous storage settings (the server was working fine at this time):

# df -h
Filesystem                        Size  Used  Avail  Use%  Mounted on
/dev/mapper/vg_test01-lv_root      95G  1.4G    88G    2%  /
tmpfs                             939M     0   939M    0%  /dev/shm
/dev/sdb1                          99G  188M    94G    1%  /tmp
/dev/sda1                         485M   54M   407M   12%  /boot

My web developer asked me to merge /tmp and / disks so this is what I did:

  1. Delete /dev/sdb1 partition using fdisk
  2. Create a new partition as LVM on /dev/sdb1 using fdisk
  3. Create a new physical volume --> pvcreate /dev/sdb1
  4. Extend volume group --> vgextend /dev/sdb1 vg_test01
  5. Extend logical volume --> lvextend -l +100%FREE /dev/vg_test01/lv_root
  6. Resize filesystem --> resize2fs /dev/vg_test01/lv_root

This is the new configuration:

# df -h
Filesystem                        Size  Used  Avail  Use%  Mounted on
/dev/mapper/vg_test01-lv_root     213G  105G    97G   52%  /
tmpfs                             939M     0   939M    0%  /dev/shm
/dev/sda1                         485M   54M   407M   12%  /boot
/usr/tmpDSK                       4.0G  145M   3.6G    4%  /tmp

Since I have the new settings my web server is throwing kernel panics quite often (around every 2 days).

The message says:

INFO: task <taskName>:<pid> blocked for more than 120 seconds.

The list of process affected that I can see from the console are:

  • mysqld
  • queueprocd
  • httpd
  • suphp
  • vmtoolsd
  • loop0
  • auditd

kernel panic screenshot

The only way I can fix this is reseting (cold reboot) the VM. I don't think it is a hardware issue as sar is not showing any bottleneck:

Linux 2.6.32-431.3.1.el6.x86_64 (test01)        08/22/2014      _x86_64_        (4 CPU)

12:00:01 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle
12:10:01 AM     all     26.86      0.01      0.98      0.57      0.00     71.57
12:20:01 AM     all      1.78      0.02      1.03      0.08      0.00     97.09
12:30:01 AM     all     26.34      0.02      0.85      0.05      0.00     72.74
12:40:01 AM     all     27.12      0.01      1.11      1.22      0.00     70.54
12:50:01 AM     all      1.59      0.02      0.94      0.13      0.00     97.32
01:00:01 AM     all     26.10      0.01      0.77      0.04      0.00     73.07
01:10:01 AM     all     27.51      0.01      1.16      0.14      0.00     71.18
01:20:01 AM     all      1.80      0.07      1.06      0.08      0.00     96.99
01:30:01 AM     all     26.19      0.01      0.78      0.05      0.00     72.96
01:40:01 AM     all     26.62      0.02      0.87      0.05      0.00     72.45
01:50:02 AM     all      1.35      0.01      0.87      0.02      0.00     97.75
02:00:01 AM     all     26.11      0.02      0.69      0.02      0.00     73.17
02:10:01 AM     all     26.73      0.02      0.89      0.14      0.00     72.21
02:20:01 AM     all      1.45      0.01      0.92      0.04      0.00     97.58
02:30:01 AM     all     26.59      0.01      1.06      0.03      0.00     72.31
02:40:01 AM     all     26.27      0.01      0.72      0.05      0.00     72.95
02:50:01 AM     all      0.86      0.01      0.50      0.09      0.00     98.53
03:00:01 AM     all     25.61      0.02      0.39      0.03      0.00     73.96
03:10:01 AM     all     26.30      0.08      0.66      0.14      0.00     72.82
03:20:01 AM     all      0.81      0.01      0.51      0.04      0.00     98.63
03:30:02 AM     all     26.15      0.02      0.53      0.07      0.00     73.24
03:40:01 AM     all     26.06      0.01      0.47      0.04      0.00     73.42
03:50:01 AM     all      0.96      0.02      0.51      0.03      0.00     98.48
Average:        all     17.69      0.02      0.79      0.14      0.00     81.36

06:58:14 AM       LINUX RESTART

07:00:01 AM     CPU     %user     %nice   %system   %iowait    %steal     %idle
07:10:01 AM     all      1.04      0.02      0.57      0.95      0.00     97.42
07:20:02 AM     all      0.66      0.01      0.39      0.06      0.00     98.87
07:30:01 AM     all     25.71      0.01      0.45      0.16      0.00     73.67
07:40:01 AM     all     25.88      0.01      0.35      0.08      0.00     73.68
07:50:01 AM     all      1.13      0.02      0.55      0.11      0.00     98.19

As you can see the server became unresponsive at 03.50 AM and I had to reset the VM at 06.58 AM to bring the website up again.

I would appreciate any help/assistance to fix this issue.

thank you very much

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